[clr-interp] Enable rejit in the interpreter (#122626)

- Rely on resetting the interpreter code pointer to trigger the existing
rejit/prestub logic to fill in any gaps we have.

This fixes the rejit test

---------

Co-authored-by: Copilot <[email protected]>

Author: davidwrighton

src/coreclr/vm/codeversion.cpp

@@ -1980,7 +1980,11 @@ HRESULT CodeVersionManager::PublishNativeCodeVersion(MethodDesc* pMethod, Native
                 pMethod,
                 nativeCodeVersion.GetVersionId()));
 
-        #ifdef FEATURE_TIERED_COMPILATION
+#ifdef FEATURE_INTERPRETER
+            // When we hit the Precode that should fixup any issues with an unset interpreter code pointer. This is notably most important in ReJIT scenarios
+            pMethod->ClearInterpreterCodePointer();
+#endif
+#ifdef FEATURE_TIERED_COMPILATION
             bool wasSet = CallCountingManager::SetCodeEntryPoint(nativeCodeVersion, pCode, false, nullptr);
             _ASSERTE(wasSet);
         #else

src/coreclr/vm/method.cpp

@@ -3233,6 +3233,10 @@ void MethodDesc::ResetCodeEntryPoint()
     WRAPPER_NO_CONTRACT;
     _ASSERTE(IsVersionable());
 
+#ifdef FEATURE_INTERPRETER
+    ClearInterpreterCodePointer();
+#endif
+
     if (MayHaveEntryPointSlotsToBackpatch())
     {
         BackpatchToResetEntryPointSlots();
@@ -3265,6 +3269,10 @@ void MethodDesc::ResetCodeEntryPointForEnC()
         return;
     }
 
+#ifdef FEATURE_INTERPRETER
+    ClearInterpreterCodePointer();
+#endif
+
     LOG((LF_ENC, LL_INFO100000, "MD::RCEPFENC: this:%p - %s::%s\n", this, m_pszDebugClassName, m_pszDebugMethodName));
 #ifndef FEATURE_PORTABLE_ENTRYPOINTS
     LOG((LF_ENC, LL_INFO100000, "MD::RCEPFENC: HasPrecode():%s, HasNativeCodeSlot():%s\n",